Fish aggregating device

A fish aggregating (or aggregation) device (FAD) is a man-made object used to attract pelagic fish such as marlin, tuna and mahi-mahi (dolphin fish). They usually consist of buoys or floats tethered to the ocean floor. FADs attract fish for reasons that vary by species.

Fish tend to move around FADs in varying orbits, rather than remaining stationary below the buoys. Both recreational and commercial fisheries use FADs.

Before FADs, commercial tuna fishing used purse seining to target surface-visible aggregations of birds and dolphins, which were a reliable signal of the presence of tuna schools below. The demand for dolphin-safe tuna was a driving force for FADs. In the past, people in the Pacific islands used bamboo rafts to make it easier to catch tuna that gathered below. FAD use has made fishing much easier.